off()

/**
 * @param  {String} event name
 * @param  {Function} callback
 * @return {Void}
 */
off(eventName, callback)

---

Removes a custom callback from an instance.

---

Example

const fn = (e, selected, unselected) => {
    counter.value = selected.length;
};

selectable.on("end", fn);

// Later

selectable.off("end", fn);